Summer drought and spring frost, but not their interaction, constrain European beech and Silver fir growth in their southern distribution limits

Climate warming has lengthened the growing season by advancing leaf unfolding in many temperate tree species. However, an earlier leaf unfolding increases also the risk of frost damage in spring which may reduce tree radial growth. In equatorward populations of temperate tree species, both late frosts and summer droughts impose two constraints to tree growth, but their effects on growth are understudied. We used a tree-ring network of 71 forests to evaluate the potential influence of late frosts and summer droughts on growth in two tree species that reach their southern distribution limits in north-eastern Spain: the deciduous European beech (Fagus sylvatica L.) and the evergreen Silver fir (Abies alba Mill). The occurrence of late frost events and summer drought was quantified by using a high-resolution daily temperature and precipitation dataset considering the period 1950 2012. Late frosts were defined as days with average temperature below 0 °C in the site-specific frost-free period, whereas drought was quantified using the 18 month-long August Standardized Precipitation Evapotranspiration Index (SPEI). The growth of European beech and Silver fir was reduced by the occurrence of both late frost events and summer drought. However, we did not find a significant interaction on growth of these two climate extremes. Beech was more negatively impacted by late frosts, whereas Silver fir was more impacted by summer drought. Further studies could use remote-sensing information or in situ phenological records to refine our frost index and better elucidate how late frosts affect growth, whether they interact with drought to constrain growth, and how resilience mechanisms related to post-frost refoliation operate in beech. © 2019 Elsevier B.V

Étude de revêtements intumescents sous flux solaire concentré et modélisation numérique

La protection des matériels militaires contre les agressions thermiques est uneproblématique capitale dans le domaine de la défense. Dans ce contexte, les revêtements intumescents offrent une solution efficace et aisée à mettre en oeuvre : lorsqu’ils atteignent une température seuil, ces revêtements gonflent pour former une couche isolante performante. Cette étude présente une série d’essais expérimentaux réalisés au moyen d’un four solaire de 45 kW et propose la méthode de la transformation de Landau pour faciliter la modélisation des phénomènes de gonflement

Ensayo clínico aleatorizado de una intervención intensiva sobre los estilos de vida de pacientes con hiperfibrinogenemia en prevención primaria de las enfermedades cardiovasculares en el ámbito de la atención primaria de salud

ObjetivosEstudiar el efecto de un programa intensivo de modificación del estilo de vida en los valores de fibrinógeno plasmático en pacientes sin enfermedad cardiovascular, con fibrinógeno elevado y valores normales de colesterol. Analizar si el efecto sobre el fibrinógeno es independiente del efecto sobre los lípidos.DiseñoEnsayo clínico controlado y aleatorizado.EmplazamientoOnce áreas básicas de L’Hospitalet de Llobregat y Barcelona.ParticipantesSe incluirá a 436 pacientes, 218 en cada grupo, de 35-75 años, sin enfermedad cardiovascular (cardiopatía isquémica, accidente cerebrovascular y arteriopatía periférica) con hiperfibrinogenemia (fibrinógeno > 300 mg/dl) y colesterol plasmático < 250 mg/dl.IntervencionesUn grupo de pacientes recibirá una intervención intensiva (en frecuencia e intensidad del consejo y tratamiento) sobre cambios de estilo de vida: dejar de fumar, dieta hipocalórica en caso de sobrepeso u obesidad y ejercicio físico. El seguimento del grupo intervención se realizará cada 2 meses. El grupo control seguirá los cuidados habituales.MedicionesSe determinarán los valores de fibrinógeno plasmático. Además, se registrarán otros acontecimientos de interés (modificación de los factores de riesgo, cambios en la calidad de vida, acontecimientos cardiovasculares y muerte) durante un seguimiento de 2 años.DiscusiónLa instauración de una intervención intensiva de prevención primaria (cambios de estilo de vida) en los pacientes que presentan hiperfibrinogenemia podría ser una medida más eficaz que la intervención habitual para reducir las cifras de fibrinógeno plasmático. Además, estas medidas podrían traducirse en una disminución del riesgo cardiovascular y en una mejora de la calidad de vida del paciente.ObjectivesTo study the effect of an intensive programme to modify life-style on levels of plasma fibrinogen in patients without cardiovascular pathology, with high fibrinogen and normal cholesterol levels. To analyse whether the effect on fibrinogen is independent, or otherwise, of the effect on lipids.DesignRandomised clinical trial with a control.Setting11 health districts in L’Hospitalet de Llobregat and Barcelona.Participants436 patients will be included, 218 individuals between 35 and 75 years old in each group, and without cardiovascular pathology (ischaemic cardiopathy, cerebral vascular accident or peripheral arteriopathy), with hyperfibrinogenaemia (fibrinogen ›300 mg/dL) and with plasma control ‹250 mg/dL.InterventionsOne group of patients will receive an intensive intervention (in frequency and intensity of counselling and treatment) for life-style changes, i.e. stopping smoking, low-calorie diet in case of overweight or obesity, and physical exercise. The follow-up of the intervention group will be every 2 months. The control group will follow customary treatments.MeasurementsLevels of plasma fibrinogen. In addition, other relevant events will be recorded over a 2-year monitoring period: modification of risk factors, changes in quality of life, cardiovascular events or death.DiscussionThe introduction of an intensive primary prevention intervention (life-style changes) in patients with hyperfibrinogenaemia could be a more effective measure than the habitual intervention for reducing plasma fibrinogen figures. In addition, these measures could be translated into a reduction of cardiovascular risk and an improvement in the patient́s quality of life

Evaluation du risque de brûlure par exposition à des rayonnements lasers. Expérimentations et modélisation.

La technologie laser étant de plus en plus utilisée, l\u27objectif de cette étude est de déterminer quel type d\u27agression laser entraîne quel dégât (brûlure) sur la peau. Il existe en effet unedifférence de diagnostic et de pronostic des lésions en fonction de la longueur d’onde du laser utilisé. Pour ce faire, des expérimentations in vivo sur modèle animal ont été menées à l\u27aide de trois lasers émettant respectivement à 808 nm, 1,94 μm et 10,6 μm. Parallèlement, un modèle mathématique permettant de simuler l\u27effet thermique d\u27une agression laser sur la peau a été développé

A genome-wide linkage analysis for reproductive traits in F2 Large White × Meishan cross gilts

Female reproductive performance traits in pigs have low heritabilities thus limiting improvement through traditional selective breeding programmes. However, there is substantial genetic variation found between pig breeds with the Chinese Meishan being one of the most prolific pig breeds known. In this study, three cohorts of Large White × Meishan F(2) cross-bred pigs were analysed to identify quantitative trait loci (QTL) with effects on reproductive traits, including ovulation rate, teat number, litter size, total born alive and prenatal survival. A total of 307 individuals were genotyped for 174 genetic markers across the genome. The genome-wide analysis of the trait-recorded F(2) gilts in their first parity/litter revealed one QTL for teat number significant at the genome level and a total of 12 QTL, which are significant at the chromosome-wide level, for: litter size (three QTL), total born alive (two QTL), ovulation rate (four QTL), prenatal survival (one QTL) and teat number (two QTL). Further support for eight of these QTL is provided by results from other studies. Four of these 12 QTL were mapped for the first time in this study: on SSC15 for ovulation rate and on SSC18 for teat number, ovulation rate and litter size